The present invention relates to a waste heat boiler for cooling partial oxidation crude gas with an integrated crude gas-clean gas heat exchanger.
The German document DE-OS No. 3,505,157 discloses a process of generation of electrical energy in a combined gas and steam turbine power unit with a pre-connected coal gasifying device. In this system the dedusted and desulfurized clean gas before its introduction into a combustion engine of a gas turbine, is pre-heated in an indirect heat exchange with the hot partial oxidation crude gas to a temperature 200.degree.-500.degree. C. This heat exchange must be performed in a crude-clean gas heat exchanger with heat exchanging surfaces which are integrated in the waste heat boiler of the coal gasifying device.
With these process steps a maximum portion of the tangible heat of the hot partial oxidation crude gas which is discharged from the coal gasifying device must be transferred to the cold dedusted and desulfurized clean gas which is supplied to the combustion chamber of the gas turbine. On the other hand, by the arrangement of the crude gas-clean gas heat exchanger inside the waste heat boiler, it is possible better than with the conventional heat exchanger to eliminate incrustations and dirt on the crude gas side of heat exchanger surfaces. The above mentioned reference does not disclose however any details of the construction of such a waste heat boiler with an integrated crude gas-clean gas heat exchanger.